1. Field of the Invention
The present invention relates to image processing systems, particularly to an image processing system including a synchronous type processing unit and an asynchronous type processing unit.
2. Description of the Related Art
A conventional image processing apparatus is known that reads out image data stored in a memory to carry out image processing on the read out image data. The image processing apparatus can be formed of a synchronous type or an asynchronous type circuit. A hardware circuit such as the ASIC (application specific integrated circuit) is exemplary of the synchronous type circuit. A circuit that carries out a process with software formed of a MPU (microprocessor) and the like is exemplary of the asynchronous type circuit.
The conventional image processing apparatus imposes problems set forth in the following.
In an image processing apparatus entirely formed of the synchronous type circuit, the processing speed is determined by the process of the heavy load. There was a problem that the process is slowed down even if it is not necessary to carry out a heavy load process. This is because a process corresponding to the time consumed for the heavy load process is required whatever image data is processed. For example, in a synchronous type circuit 900 shown in FIG. 11 including a line memory 901, a matrix processing unit 903 and a γ correction unit 905, data delay occurs since image data of N lines must always be stored in line memory 901. Also, since a complicated matrix operation process (for example, integration of floating point) is carried out, data (operational result) delay occurs.
When the entirety is implemented by the synchronous type circuit, the synchronous circuit per se becomes complex and lacks flexibility. When the resolution or the like of the image data is altered, the entire structure of the apparatus must be modified, resulting in increase in cost.
When the entirety of the image processing apparatus is implemented by the asynchronous type circuit, high speed processing is degraded.